The most effective solution for a wet basement is an exterior drain tile system. Though very effective at controlling basement water, an exterior system is very costly, and requires major excavation around the entire foundation. Some choose to install a drainage channel above the concrete slab. This is the simplest and least costly type of system, and may be effective for poured concrete walls where cracking is the main point of entry for water. However, this does not solve the problem in block walls because water will continue to pool in the block cores. Another type of system places a drainage channel in the edge of the slab, on top of the footing. Unfortunately, footings don’t provide a continuous slope to the sump basin and water will stand in the channel for a very long time. Also, the blocks are below the level of the slab and tend to sit in water which allows them to become damp. The small drainage channels can be overtaken by water flow during extreme rains, leading to more leaking, and many of these systems leave an open gap between the floor and wall. The best alternative is a sub-slab rigid drain tile system (according to the University of MN). By placing the drain tile alongside the footing, water is allowed to drain to a level beneath the slab where it can travel to the sump pit and be pumped away from your home.
